FILE - In this May 8, 2013, file photo, Rep. Trey Gowdy, R-S.C., questions a witness during the House Oversight and Government Reform Committee's hearing on Benghazi on Capitol Hill in Washington. The Obama administration and House Democrats said May 5, 2014, they were undecided about whether to take part in or boycott an election-year investigation by Republicans into the Benghazi attack that killed four Americans. House Speaker John Boehner announced last week he would create a select committee to examine the response to the deadly Sept. 11, 2012, assault on the U.S. diplomatic post in Libya that killed Ambassador Chris Stevens and three other Americans and today Boehner said Gowdy would head the investigation. (AP Photo/Cliff Owen, File)

House Democrats opened the door Tuesday to participating in a special panel's investigation of Benghazi, even if they see it as little more than an election-year ploy by Republicans to discredit the Obama administration and motivate GOP voters.

Laying out her party's conditions, Minority Leader Nancy Pelosi said Republicans must conduct interviews and share information as part of their new inquest into the Obama administration's response to the Sept. 11, 2012, attack on the U.S. diplomatic post in Libya.

She called for the same number of Democrats as Republicans on the panel, a demand the GOP majority immediately rejected.

"If this review is to be fair, it must be truly bipartisan," said Pelosi, D-San Francisco.

With midterm elections looming closer, Republicans are sharpening their focus on the Benghazi attack that killed Ambassador Chris Stevens and three other Americans. A vote to authorize the probe is expected this week.

A senior GOP congressman has issued a subpoena to Secretary of State John Kerry to testify before a separate committee. And the subject could surface in multiple other congressional hearings this week.

House Speaker John Boehner has yet to outline his full plan for the select panel, whose establishment is all but a formality in the GOP-controlled House. But the Republican chosen by Boehner to head the investigation said Democrats wouldn't get the same number of seats on the committee.

"Look, we're in the majority for a reason. We have more seats in the House," said Rep. Trey Gowdy, a second-term congressman from South Carolina and former prosecutor. He called Pelosi's comments a "good sign" that she is considering Democratic participation.

Twenty months since the attack, Republicans have made Benghazi a central plank of their strategy to win control of the Senate in November's elections.

Democrats are in a bind. They don't want their presence to provide credibility to what they believe will be a partisan forum for attacks on the president and his top aides. But boycotting would mean losing the ability to counter Republican claims.